糖尿病与口腔健康：双向关系与日常护理

If you live with diabetes, your gums and teeth deserve the same attention as your blood sugar readings. Diabetes and oral health affect each other in both directions: high blood glucose makes gums prone to inflammation, and long-standing periodontitis makes glucose harder to control. Here is the key evidence and the care habits worth adopting.

How are diabetes and oral health connected?

• Blood sugar affects the gums: according to NIDDK (the US National Institute of Diabetes and Digestive and Kidney Diseases), high glucose raises sugar in saliva, feeds plaque-forming bacteria and makes mild gum disease more likely to become severe periodontitis.
• Inflamed gums affect blood sugar: the 2018 consensus report of the International Diabetes Federation (IDF) and the European Federation of Periodontology (EFP) found that people with diabetes and periodontitis tend to have higher HbA1c than those with healthy gums, and that periodontitis is linked to a higher risk of type 2 diabetes (Sanz et al., PubMed).
• Latest guidance: the American Diabetes Association's Standards of Care 2026 say periodontal disease is more severe, possibly more common, in people with diabetes and is associated with higher HbA1c (Diabetes Care 2026).
• How common: the American Dental Association's MouthHealthy site says about 22% of people with type 1 or type 2 diabetes have periodontal disease.

Does periodontal treatment lower HbA1c?

The Cochrane review by Simpson and colleagues (2022) pooled 35 trials with 3,249 people, comparing subgingival instrumentation (scaling and root surface cleaning) with no treatment or usual care (PubMed):

• At 3–4 months: HbA1c fell by about 0.43 percentage points more (30 studies, 2,443 people).
• At 6 months: about 0.30 percentage points (12 studies, 1,457 people).
• At 12 months: about 0.50 percentage points, but from only 1 study of 264 people.

The evidence was rated moderate certainty. The earlier IDF–EFP report cited a 0.27–0.48% reduction after 3 months and noted that long-term data were inconclusive. Periodontal care is a support, not a substitute for medication, diet or exercise prescribed by your doctor.

Other mouth problems to watch for

According to NIDDK, people with diabetes are also more likely to have:

• Dry mouth: the disease and some medicines reduce saliva, raising the risk of cavities and sores. See our article on dry mouth causes and relief.
• Thrush: a fungal infection causing painful white patches in the mouth.
• Slow healing: high glucose raises the risk of infection after oral surgery and slows healing; Cedars-Sinai advises telling your dentist about ulcers that do not heal.
• Tooth loss: in the US, almost 25% of adults aged 50+ with diabetes have severe tooth loss, versus about 16% of those without diabetes.

See a dentist early if your gums are red, swollen, bleed easily or recede, if teeth feel loose, or if bad breath persists after brushing. If your gums often bleed when you brush, read our article on bleeding gums.

How should you prepare for a dental visit?

Recommendation 4.15 of the Standards of Care 2026: people with diabetes should be referred for a dental exam at least once a year. Before your appointment:

• Tell your dentist you have diabetes, for how long, any complications and which medicines you take (NIDDK).
• Eat and take your medicine as usual: Cedars-Sinai advises taking your medicine as normal and bringing your medicine, a snack and a source of sugar in case of low blood sugar. Do not skip breakfast.
• Ask your diabetes doctor before an extraction or major procedure: how to monitor glucose and whether to change doses or timing (NIDDK). The American Diabetes Association notes that people on insulin, sulfonylureas or meglitinides are at risk of hypoglycaemia during procedures.
• Accept a delay for some dental work if your blood sugar is not under control (Cedars-Sinai).

Daily oral care for people with diabetes

Four basics that NIDDK, MouthHealthy and Vinmec all stress:

1. Keep blood glucose stable: take medicines, eat and stay active according to your doctor's targets.
2. Brush and clean between teeth every day: brush twice a day for at least 2 minutes with a soft brush, and clean between teeth at least once a day.
3. Tell your dentist you have diabetes: with your medicine list and latest HbA1c result if you have it.
4. Have regular dental check-ups: at least once a year, or more often if your dentist advises.

A few more tips:

• Use fluoride toothpaste (CDC); see our articles on fluoride toothpaste and how to brush properly.
• Clean between teeth with floss, interdental brushes or a water flosser, whichever you can keep up daily; Vietnam's Vinmec (Vietnamese source) also recommends flossing at least once a day.
• Once a week, check your gums in a mirror under good light for dark red, swollen or receding areas.

Diabetes and oral health in Vietnam: why check early?

Vietnamese newspaper Bao Dau tu (Vietnamese source), citing a 2021 Ministry of Health survey, reports that about 7.1% of Vietnamese adults have diabetes, close to 5 million people, yet only about 35% have been diagnosed. The IDF Diabetes Atlas review (Borgnakke, 2019) suggests dentists can spot signs of undiagnosed dysglycaemia and refer patients for evaluation (PubMed). If your dentist sees unusually severe gum inflammation and suggests a glucose test, take it seriously.

Suggested tools from Inmax

• M159: a water flosser with a curved, hand-hugging body, 256 g, 300 ml tank, 4 modes (Pulse/Soft/Normal/Power), 40–130 PSI. If gums are inflamed, start on Soft.
• M5: an electric toothbrush with a Gum Care mode alongside Clean, Sensitive and Whitening; 1,200 mAh battery, Type-C charging, IPX7.

You can compare specifications or contact Inmax for advice.

Frequently asked questions

Can people with diabetes have extractions or implants?

Usually yes, coordinated with the doctor treating your diabetes. Cedars-Sinai notes that implants are more likely to fail when diabetes is poorly controlled.

Does a professional cleaning lower blood sugar?

In the 2022 Cochrane review, HbA1c fell by about 0.43 percentage points more at 3–4 months. It is a supporting effect, not a replacement for diabetes treatment.

How often should I see a dentist?

The American Diabetes Association recommends at least once a year; Cedars-Sinai says every 6 months is best.

Can people with diabetes use a water flosser?

We found no official source advising against it; start on a gentle setting.

This overview of diabetes and oral health is for general information, based on the sources linked above; talk to your doctor and dentist before changing your treatment or oral care.